Andrena (Habromelissa) angustula, Wood, 2023

Wood, Thomas James, 2023, New Old World Andrena species, with a focus on Turkey (Hymenoptera: Andrenidae), Zootaxa 5266 (1), pp. 1-72 : 8-12

Andrena (Habromelissa) angustula spec. nov.

HOLOTYPE: MONGOLIA: W [West], 40 km SW Uliastay [Uliastai], dunes [inferred 47.4474 oN, 96.3626 oE], 18.vii.2005, 1♁, leg. J. Halada, OÖLM.

PARATYPES: MONGOLIA: W [ West ], 40 km SW Uliastay [Uliastai], dunes, 18.vii.2005, 1♁, leg. J. Halada, OÖLM ; W [ West ], 15 km N Altay [Altai] city, 15.vii.2005, 2♁, leg. J. Halada, OÖLM / TJWC ; Chuluut Gol (riv.), 1940 m, 23.vii.2005, 1♀, leg. J. Halada, OÖLM ; 50 km SW Choibalsan , 960 m, 25.vii.2007, 1♀, leg. J. Halada, OÖLM .

Description: Female: Body length: 7–8 mm ( Figure 3A ). Head: Dark, 1.2 times wider than long ( Figure 3B ). Clypeus weakly domed, subtly flattened medially, irregularly punctate, punctures almost confluent to separated by 2 puncture diameters; underlying surface basally and laterally shagreened and weakly shining, becoming smooth and shining at apical margin. Process of labrum unusual, with strong 90 degree angle separating frontal and ventral parts; viewed frontally process of labrum short, twice as wide as long, rectangular; viewed ventrally, forming rounded semi-circular shape, slightly wider than long. Gena equalling width of compound eye; ocelloccipital distance equalling 1 diameter of lateral ocellus. Foveae dorsally broad, occupying three quarters of space between lateral ocellus and compound eye, slightly narrowed ventrally at level of antennal insertions; filled with whitish to light brownish hairs ( Figure 3C ). Face, gena, vertex, and scape with short white hairs. Antennae dark, A4–12 slightly lightened ventrally by presence of grey scales, A3 subequal to A4+5+6. Mesosoma: Scutum and scutellum clearly but variably punctate, punctures separated by 0.5–2 puncture diameters, underlying surface shagreened and dull in anterior quarter, smooth and shining over remaining disc ( Figure 3D ). Pronotum with weak humeral angle. Mesepisternum and dorsolateral parts of propodeum densely microreticulate and dull; propodeal triangle poorly defined laterally, internal surface with irregular network of raised rugae in basal two thirds, apical one third granulate ( Figure 3E ). Mesepisternum with moderately long white hairs, scutum and scutellum with shorter white hairs; propodeal corbicula incomplete, dorsally composed of short and finely plumose whitish hairs, internal surface with many fine, simple white hairs. Legs dark, pubescence whitish, flocculus very weak, composed of white plumose hairs, femoral and tibial scopa white. Hind tarsal claws with short inner tooth. Wings hyaline, stigma and venation orange, nervulus antefurcal. Metasoma: Terga variably red-marked, from T1–3 entirely and T4 partially red-marked to T1 apically, T2 entirely, and T3 basally red-marked; T2 with small pair of lateral black spots; remaining terga dark ( Figure 3F ). Terga strongly punctured, punctures separated by 1–2 puncture diameters, punctures covering both discs and margins; tergal margins weakly depressed, most evident on T4. T2–4 with weak lateral hair fringes of sparse and obscure whitish hairs. Apical fringe of T5 and hairs flanking pygidial plate whitish to orangish-brown, pygidial plate narrowly triangular with strongly raised longitudinal ridge medially.

Male: Body length: 7 mm ( Figure 4A ). Head: Dark, 1.2 times wider than long ( Figure 4B ). Clypeus weakly domed, coloured ivory-white with exception of two dark triangular marks laterally; clypeus clearly but shallowly punctate, punctures separated by 1–2 puncture diameters, underlying surface subtly shagreened, weakly shining. Gena clearly exceeding width of compound eye, slightly produced into rounded angulation lateroventrally; ocelloccipital distance equalling 1 diameter of lateral ocellus ( Figure 4C ). Process of labrum narrow, apically projecting beyond vertical profile of clypeus ( Figure 4D ), ventral surface with shallow longitudinal impression. Mandibles long, falcate, crossing apically, with inner subapical tooth. Face, gena, vertex, and scape with white hairs, none equalling length of scape. Antennae dark, A3 slightly exceeding A4+5, much shorter than A4+5+6. Mesosoma: Mesosoma structurally as in female, though pronotum with much stronger humeral angle, here forming shining vertical furrow. Mesosoma with long white hairs, none exceeding length of scape. Legs dark, apical tarsal segments lightened dark reddishbrown, pubescence whitish. Hind tarsal claws with short inner tooth. Wings hyaline, stigma and venation orange, nervulus antefurcal. Metasoma: Terga structurally as in female, with same colouration ( Figure 4E ). S8 narrow, slightly broadened apically, apically with shallow median emargination. Genital capsule compact, gonocoxae produced into narrow sharply pointed teeth, gonostyli apically broadened and spatulate, dorsal surface with golden hairs ( Figure 4F ). Penis valves basally broad, visible on either side of gonocoxal teeth, narrowing medially.

Diagnosis: Andrena angustula can be placed in the subgenus Habromelissa most clearly due to male characters, specifically the combination of long mandibles, these crossing apically ( Figure 4D ), clypeus yellow-marked ( Figure 4B ), pronotum with clear humeral angle, process of labrum protuberant ( Figure 4D; c.f . subgenus Cnemidandrena ), and genital capsule with gonocoxa clearly produced apically into sharp teeth ( Figure 4F ). Diagnosis of females is more challenging, as many of the characters described by Hirashima and LaBerge ( Hirashima 1964) appear to be typical to the type species A. omogensis Hirashima, 1953 as opposed to being true subgeneric characters (e.g. the wing venation, specifically the position of the second recurrent vein which joins the third submarginal cell essentially at its apex [contrast Figures 3A , 4A ], the shiny dorsolateral parts of the propodeum). Females of A. angustula should be recognised as Habromelissa by their relatively small body size, their slim appearance, pronotum with weak humeral angle, foveae occupying more than half of space between lateral ocellus and compound eye ( Figure 3C ), foveae not extending ventrally below the level of the antennal insertions, clypeus slightly domed ( Figure 3B ), and terga partly red-marked ( Figure 3F ).

This group of bees is poorly studied, with only four species known from China, Taiwan, and Japan ( Table 1), three species of which are known only from the type series. The subgenus is unusual in that species mostly emerge in the autumn, a behaviour that is rare within Old World Andrena . Species diagnosis is challenging because only the female is known for A. qinhaiensis Xu, 1994 and only the male is known for A. batangensis Xu, 1994 and A. nantouensis Dubitzky, 2006 . Female A. angustula can be separated from A. qinhaiensis by the dark hind tibiae (versus orange hind tibiae), the dull clypeus (versus shiny clypeus), ocelloccipital distance subequal to diameter of lateral ocellus (versus ocelloccipital distance equalling 0.5 times diameter of lateral ocellus), clypeus microreticulate and dull (versus clypeus smooth and shining), and foveae filled with light brown hairs (versus foveae filled with dark brown hairs). Apart from the non-overlapping distributions, they can be separated from the Japanese endemic A. omogensis by the position of the second recurrent cross vein which connects to the third submarginal cell well before its apex (versus second recurrent cross vein meeting the third submarginal cell at or immediately before its apex) and the clypeus which is shagreened over the majority of its area, becoming shiny only at its apex (versus clypeus smooth and shiny over almost its entire area).

Andrena angustula males can be separated from A. batangensis as the clypeus is clearly punctate ( Figure 4B ) and finely shagreened (clypeus impunctate and smooth and shining in A. batangensis ) and the scutum is smooth and shiny (versus scutum with interspaces shagreened, weakly shiny). Andrena angustula males can be separated from A. omogensis by the broad gena that is clearly broader than the width of the compound eye ( Figures 4C, 4D ), the surface shiny and clearly punctate (gena clearly narrower than the width of the compound eye, the surface shagreened and dull in A. omogensis ). Andrena omogensis is also currently known only from Japan. Andrena angustula males can be immediately separated from A. nantouensis by the red-marked terga (uniformly black-brown in A. nantouensis ) but also by the different genital capsule with short and narrow pointed gonocoxal teeth (gonocoxal teeth elongate, with broad bases, obscuring the base of the penis valves in dorsal view in A. nantouensis ). Andrena nantouensis is also restricted to the island of Taiwan ( Dubitzky 2006).

Etymology: Feminine form of the Latin adjective angustus meaning narrow, with the addition of the diminutive suffix to signify both small and narrow in reference to its body shape.

Distribution: Mongolia.

Comparative material examined. Andrena qinhaiensis : CHINA: Kansu mer . [Gansu], Xiahe Labrang [Labrang Monastery], 1–15.vi.1998, 1♀, leg. V. Major, OÖLM .

Figures

FIGURE 3. Andrena (Habromelissa) angustula spec. nov. female. A. Habitus, lateral view, B. Face, frontal view, C. Head, dorsal view, D. Scutum, dorsolateral view, E. Propodeum, dorsal view, F. Terga, dorsal view.

FIGURE 4. Andrena (Habromelissa) angustula spec. nov. male.A. Habitus, lateral view, B. Face, frontal view, C. Head, lateral view, D. Head, reverse lateral view, mandible and process of labrum detail, E. Terga, dorsal view, F. Genital capsule, dorsal view.